This invention relates to edible food compositions. More particularly, this invention relates to food compositions containing certain fat-like esters having the physical characteristics of, but which are less readily digested or absorbed than harmful triglyceride fats such as saturated fats and trans-unsaturated fats contained in hardstock of prior used fat blends. These fat-like esters are substituted for some part of the hardstock as texturizers in the food.
Fats constitute a substantial portion of the total calories in the human diet. In many individuals, fats contribute as much as 40% of the calories consumed. Fat is an important source of energy and contains essential fatty acids, such as linoleic and linolenic acids. Fat is also a carrier for fat-soluble vitamins and other nutrients. In addition to its functional properties, fat is often used to improve the overall quality of foods, including color, texture, structure, flavor and mouthfeel. However, in recent decades, investigations have revealed a correlation between high consumption of fats and increased rates of diseases such as atherosclerosis, coronary artery disease and obesity. Furthermore, it has been observed that saturated fatty acids and trans-unsaturated fatty acids are a greater contributor to diseases such as coronary arterial disease than other types of fats. Thus, over the years, the amount of fat-derived calories in the human diet, as well as the proportion of saturated to unsaturated fats consumed by the population, has changed significantly. The consumption of fats derived from vegetable oils that are rich in cis-unsaturated fatty acids has increased markedly over the years. However, in a number of food products, the complete substitution of saturated fats with unsaturated fats leads to other problems.
Fat blends used in the production of fat-containing products like margarines, spreads and spreadable cheeses, consist of a liquid oil fraction and a so-called hardstock. The liquid oil fraction typically comprises liquid unmodified vegetable oils such as soybean oil, sunflower oil, low erucic acid rapeseed oil (Canola), corn oil and blends of vegetable oils. Hardstock typically comprises a blend of fats that are solid at room temperature. The hardstock contains a high proportion of triglycerides that crystallize to give the final product certain desired physical properties such as texture, creaminess and melt-down in the mouth. Texture typically encompasses a number of desired characteristics such as viscosity, plasticity, solid fat content versus temperature and melting point. For many fat-containing foods such as margarines, spreads and confections, a steep melting curve with nearly complete melting in the range of about 37° C. to about 40° C. approximating body temperature is desirable. Usually, the hardstock is made from naturally occurring hard fats such as tropical oils and animal fat, or fats that are prepared by either partial or full hydrogenation of liquid oils with or without subsequent co-esterification with liquid oils. Furthermore, hard fat fractions can be obtained by different fractionation procedures to obtain hard fats, which can be used as such or are subjected to further modification processes such as inter- and co-esterification. Conventionally the hardstock is composed from several different hard fats in order to obtain the desired physical properties and β′-stable fat crystals in the final product. Because of the importance of hardstock to the aesthetics of the many fat-containing foods, only a certain part of these solid saturated fats can be replaced with unsaturated oils without sacrificing the sensory quality of the product. Furthermore, the melting points of saturated and trans-unsaturated fats are higher than the equivalent cis-unsaturated acids. Thus, the higher melting fats cannot readily be replaced by the more desirable unsaturated fats without loss of texture.
A number of efforts have been undertaken in an attempt to replace at least a portion of the hardstock with other ingredients that are capable of contributing the same sensory benefits to the food product without the undesirable side effects of the saturated fatty acids and trans fatty acids. U.S. Pat. No. 5,354,573 teaches the use of fat-soluble polymers as texturizers in foods. Examples of the polymers are natural polymers such as cutin, polymers based on hydroxy acids, polymers prepared by the condensation of polyhydric alcohols and polybasic acids, polymers derived from polyvinyl alcohols, fatty acid esters of acrylates and polyethylene glycol fatty acid derivatives.
EPO Patent Publication No. 4070658A1 attempts to reduce the percentage of hardstock of edible spreads to a minimum, representing less than 10% by weight of fully hydrogenated fat with a low trans-unsaturated fatty acid content. The remaining fat is derived from liquid oil and is largely unsaturated.
Much effort has been undertaken to replace triglycerides with fully or only partially absorbable synthetic fats. U.S. Pat. No. 3,600,186 discloses synthetic sugar fatty acid esters and sugar alcohol fatty acid esters having at least four fatty acid ester groups. These compounds are said to have the physical properties of ordinary triglyceride fat, but are not digested or absorbed to the same extent as the natural fat when eaten. EPO Patent Publication No. 0375027B1 discloses an edible composition comprising blends of solid and liquid non-digestible fatty material that can be used to replace triglyceride fats in foods. The non-digestible fatty material is a polyol fatty acid polyester, such as sugar fatty acid polyester, sugar alcohol fatty acid ester polyester, polyglycerol fatty acid polyester and mixtures thereof. This material having a particle size of 10 microns or less and a melting point higher than 37° C. is blended together with a liquid non-digestible fatty material having a melting point below 37° C. to give a product which overcomes the anal-leakage problems noted with low melting point sugar fatty acid esters or sugar alcohol fatty acid esters, such as those described in U.S. Pat. No. 3,600,186.
Another approach to obtaining a healthier fatty acid profile of the fat blend to be used in fat-containing products is to alter the composition of the hardstock to reduce to a minimum the levels of fatty acids such as lauric acid and myristic acid. Fatty acids of this type are known for their potential for increasing cholesterol levels in the blood. Typically, the hardstock is produced by co-interesterification of a fully hydrogenated vegetable oil with liquid unsaturated vegetable oils. This procedure is discussed in the Journal of the American Oil Chemists' Society (AOCS) 72, (1995), page 379-382.
Others have attempted to reduce the fat-content of margarines or spreads by the use of stabilizers such as gelatin, pectin, oligofructose and different gels such as xanthan gum, guar gum, alginate, carrageenan and cellulose derivatives. Other fat replacers have also been used in an attempt to mimic the mouth feel of the final product while reducing its total content of saturated and trans-unsaturated fat.
U.S. Pat. No. 5,502,045 discloses the use of stanol fatty acid esters, especially β-sitostanol fatty acid esters, for reducing the absorption of cholesterol. Example 5 of the patent describes a margarine which contains 80% fat. The fatty portion of the margarine was composed of 60% rapeseed oil, 35% partially hardened soybean oil and 5% coconut oil. β-sitostanol fatty acid ester in an amount of 10% and 20% by weight of the fat was added as a diluent to the fat blend. The β-sitostanol fatty acid ester served to dilute both the liquid part of the fat blend as well as the hardstock. It was determined that the margarine produced in the Example was effective in reducing the cholesterol ingestion of patients participating in an intervention study. However, there was no disclosure as to the use of such compositions as texturizers in the solid fat portion of a fat blend.
All of these approaches have certain drawbacks that make them less than a complete solution to the problem of removing harmful fats from food products while maintaining the sensory qualities imparted by those fats when present in the products.